Question 1

Which of the following best explains why ATP is considered a more universally useful form of energy for cellular processes than NADH or FADH2?

Accepted Answer

ATP can directly transfer its phosphate group to a wide variety of molecules, powering many different types of cellular work.

Question 2

During aerobic cellular respiration, which stage directly produces the most ATP via substrate-level phosphorylation?

Accepted Answer

Glycolysis

Question 3

Which of the following correctly matches the location of each stage of aerobic cellular respiration in a eukaryotic cell?

Accepted Answer

Glycolysis: cytoplasm; Citric acid cycle: mitochondrial matrix; Electron transport chain: inner mitochondrial membrane

Question 4

Which of the following is a product of fermentation in human muscle cells under anaerobic conditions?

Accepted Answer

Lactic acid

Question 5

What is the main reason that oxidative phosphorylation cannot occur in the absence of oxygen?

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain, allowing electrons to flow and ATP to be produced.

Question 6

Which of the following best describes the role of NADH and FADH2 in cellular respiration?

Accepted Answer

They carry high-energy electrons to the electron transport chain, where their energy is used to generate a proton gradient.

Question 7

If a poison specifically inhibits the function of Complex I in the electron transport chain, which of the following would be the most immediate effect?

Accepted Answer

NADH would be unable to donate electrons, reducing ATP production from NADH.

Question 8

Which of the following equations correctly represents the net reaction for glycolysis?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 2\ \mathrm{NAD}^+ + 2\ \mathrm{ADP} + 2\ \mathrm{P_i} \rightarrow 2\ \mathrm{pyruvate} + 2\ \mathrm{NADH} + 2\ \mathrm{ATP} + 2\ \mathrm{H_2O}$$

Question 9

Which of the following statements about substrate-level phosphorylation and chemiosmosis is correct?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group to ADP, while chemiosmosis uses a proton gradient to drive ATP synthesis.

Question 10

A yeast cell is placed in an anaerobic environment. Which of the following products will accumulate as a result of fermentation?

Accepted Answer

Ethanol and carbon dioxide

Question 11

Which of the following best explains why the energy yield per glucose molecule is lower in fermentation than in aerobic respiration?

Accepted Answer

Most of the energy remains in the end products (lactic acid or ethanol) rather than being extracted as ATP.

Question 12

Which of the following is a direct product of the citric acid cycle per one turn (not per glucose)?

Accepted Answer

1 ATP, 3 NADH, 1 FADH2, and 2 CO2

Question 13

Which of the following best describes the effect of a lack of oxygen on the electron transport chain and the rest of cellular respiration?

Accepted Answer

The electron transport chain stops, causing NADH and FADH2 to accumulate and glycolysis to slow due to lack of NAD+.

Question 14

Which of the following correctly orders the flow of electrons through the protein complexes of the mitochondrial electron transport chain?

Accepted Answer

Complex I → Complex II → Complex III → Complex IV

Question 15

Which of the following statements about the similarities and differences between the electron transport chains (ETC) of photosynthesis and cellular respiration is correct?

Accepted Answer

Both ETCs use a series of protein complexes to create a proton gradient, but the initial electron donors and final electron acceptors differ.

Question 16

Which molecule yields more ATP when oxidized in the electron transport chain, and why?

Accepted Answer

NADH, because it donates electrons to Complex I, resulting in more protons pumped and more ATP produced.

Question 17

A patient is diagnosed with a genetic disorder that impairs the function of the mitochondrial inner membrane. Which process would be most directly affected?

Accepted Answer

Oxidative phosphorylation

Question 18

Which of the following best describes the process of chemiosmosis in mitochondria?

Accepted Answer

Protons flow down their gradient through ATP synthase, driving the phosphorylation of ADP to ATP.

Question 19

Which of the following is a correct statement about the fate of pyruvate in the absence of oxygen in animal cells?

Accepted Answer

Pyruvate is reduced to lactic acid to regenerate NAD+ for glycolysis.

Cellular Respiration and Fermentation: Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard